Validation text crushes ValidateUploadHook dialog. Help button missing.

[Hb---]

What steps will reproduce the problem?

1. Draw a way longer than 400 m and tag it waterway=stream + layer=-1.
2. Click Upload data ...

What is the expected result?

See a dialog box with accessible buttons and see a short text about the reason of the warning because the list field has a maximum width set.

What happens instead?

Get a dialog box with scroll bars where the buttons are hardly reachable.
Get a belletristic text.

Please provide any additional information below. Attach a screenshot if possible.

Please see screenshot.

URL:https://josm.openstreetmap.de/svn/trunk
Repository:UUID: 0c6e7542-c601-0410-84e7-c038aed88b3b
Last:Changed Date: 2021-01-11 14:58:01 +0100 (Mon, 11 Jan 2021)
Build-Date:2021-01-12 02:30:54
Revision:17456
Relative:URL: ^/trunk

Identification: JOSM/1.5 (17456 en) Windows 7 64-Bit
OS Build number: Windows 7 Professional (7601)
Memory Usage: 1063 MB / 3604 MB (660 MB allocated, but free)
Java version: 1.8.0_242-b08, AdoptOpenJDK, OpenJDK 64-Bit Server VM
Look and Feel: com.sun.java.swing.plaf.windows.WindowsLookAndFeel
Screen: \Display0 1280×1024 (scaling 1.00×1.00)
Maximum Screen Size: 1280×1024
Best cursor sizes: 16×16→48×48, 32×32→48×48
VM arguments: [-Duser.language=EN]
Dataset consistency test: No problems found

[Hb---]

I refocused the feature request on the missing maxwidth setting for the list field. And a Help button is missing in this dialog too.